Kautilya's Arthashastra 9.2.24

9.2.24

praharaṇavidyāvinītaṃ tu kṣatriyabalaṃ śreyaḥ, bahulasāraṃ vā vaiśyaśūdrabalam iti //

No, says Kautilya, the enemy may win over to himself the army of Bráhmans by means of prostration. Hence, the army of Kshatriyas trained in the art of wielding weapons is better; or the army of Vaisyas or Súdras having great numerical strength (is better).